Mechanical dehydration apparatus



P 1940 E. F. ALLEN MECHANICAL DEHYDRATIQN APPARATUS Filed April 18; 1935 3 Sheets-Shed 1 INVENTOR far/e f flu. EN.

ATTORY April 9, 1940. E F ALLEN 2,196,650

MECHANICAL DEHYDRATION APPARATUS Filed April 18, 1935 5 Shefs-Sheet 2 INVENTOR I len 9 E. F- 'AL LEN I MECHANICAL DEHYDRATION APPARATUS Filed April 18, 1935 3 Sheets- Sheet 3' lNV NTOR an? I. I Hen,

ATTORNEY v Patented Apr". 9, i940- j PATENT OFFICE $196,650 MECHANICAL DEHYDMTION APPARATUS I Earle F. Allen, Scandals, N. Y., asaignor, by mesne assignmen Process tato Stacom Corporation,

Long Island City, N. Y., a corporation of New York Application April 18, 19:5, Serial No. 11,050

1: Claims. 100-47) This invention is designed to express economically and efllciently neaflyall the liquid and soluble constituents of vegetable and animal matter and is particularly applicable to the economical 5 disposition of garbage, though it can also be to advantage in the separation of cellulose and other fibre from vegetation in other conditions. The garbage collected in cities and towns is largely composed of natural cellulose fibre, which if freed fromits large natural content of liquid, is highly combustible, yielding about 7000 B. t. u.s per pound when burned. The drying of such garbage by heat suiliciently to burn it on an ordinary grate or in a mechanical stoker is, however,

1 difllcult and costly, while the odors produced are objectionable. I n

An important objectof'my present invention is to express the greater portion of such liquid by mechanical pressure so thatthe fibrous residue can then be easily ground to a fineness which will enable it to be consumed in a modern pulverized fuel burning. furnace according to the method described in my co-pending application Ser. No. 129,577 filed June 8, 1984.

The apparatus for such mechanical dehydration described in this present application is, however, so efllcient that it also removes the soluble coloring and other matter from vegetation so that the recovered cellulose fibreisclean and white, looking like cotton, andconsequently can be used for making artificial silk and other cellulose products.

The apparatus, as hereinafter described, consists in substance of a rotary, continuously acting hydraulic press. the platen surfaces of which revolve into and out of contact one with the other, intead of reciprocating toward and from one another as in hydraulic or-other presses of the prior art.

An important feature of thelapparatus herein described consists in causing said platen surfaces to travel upward to their zone of contact and then feeding the material upward to said zone, instead of downward or horizontally as has been the procedure with prior liquid expressing rolls. As a result the expressed liquid flows downward by gravity from the pressure zone and is thereby completely and automatically separated from the solid matter which is carried upward and is ulti- 5o mately delivered to any suitable discharging means entirely separate from the liquid collecting and discharging conduits.

Furthermore that dimension of the pressure zone extending in the direction of travel of the srmaterialismuchgreaterthanisthecasewith ordinary pressure rolls, so that said material is subjected to maximum pressure for a longer period, thereby giving the liquid more time in which to free itself from the solid material and drain backwards and. downwards away from it. 5"

The particular type of apparatus used comprises essentially a revoluble hollow cylinder in which is nested a roll of relatively considerable but lesser diameter, with the zone of contact located substantially on a level with the parallel 1o axes of cylinder and roll and on that side of the latter atlwhich the surfaces between which the material is compressed are traveling upward.

The innersurface of the hollow cylinder therefore serves as a conveyor element for carrying is material dumped into its interior up to and into the pressure zone. Furthermore, the described arrangement produces a more acute cross sectional angleof entry (with curved sides) to the maximum pressure zone, thereby reducing, greatly go the natural tendency of larger particles of approaching material to stop, or slowdown, their movement into the zone'by reason of the converging surfaces slipping over them; which tendency materially interferes with the efiiclencyof an or- 25 .dinary pair of opposed convex roll surfaces as arranged in ordinary rollpresses. i I V A preferred subsidiary feature of my apparatus is the inclination of the roll and cylinder axes at a considerable angle to the planeof the hori- 30 'zon, resulting in the possibility of feeding the material into the higher end of the cylinder and allowing the dehydrated solids and expressed liquids to slide or flow automatically from the lower end thereof, thereby also preventing the 35 treated material from mixing again with the raw or partly treated portions.

Incidentally, this procedure causes such portions of the solid matter as may travel around in and with the cylinder for recurrent passings through the pressure zone to follow a helical path about the cylinders axis, and thereby become subjected to progressive compression and dehydration. To that end the roll and cylinder! are given bearings one of which floats relatively to the 5 other, so that the partly,treated, more compacted material may be subjected to the same pressure as isthe incoming, more bulky, raw material. Other objects, advantages, and novel features of the invention are pointed out in the subjoined detail description of the variously modified embod-intents thereof and their respective modes of operation. The best form of apparatus embodying my invention at present known tome, to-

gather with certain modifications thereof, are illl drawings, in which v Fig. 1 is an end elevation of a dual mechanism embodying my invention. 7

Fig." 2 is a side elevation with parts omitted, and Fig. 3 is a plan view. Fig. 4 is an end elevation of another dual embodiment with parts broken away, and others shown in section.

Fig. 5 is a similar side elevation and r Fig. .6 is a plan view in the direction of arrows 8-8 in Fig. 5, with parts omitted.

Fig. 7 is an'end elevation looking in the direction of arrows I, I, of Fig. 8, with parts shown in section. r

Fig.8 is a longitudinal section on line 8-8 of Fig. 9 is an approximately horizontal section taken on line 8-8 of Fig. 8, and

Fig. 10 is a detail section, of a modified construction of cylinders and rolls.

Throughout the drawings like reference characters indicate like parts. v a,

Referring to Figs. 1, 2 and 3, indicates a suit, able supporting frame in which are supported two hollow cylinders 2, 2, which, as shown, are supported and held in position by a plurality of anti-friction idler wheels or rolls .3, 8, so that the side surfaces of the cylinder exteriors are closely adjacent one to another, or in actual contact. 4, 4, indicate two preferably solid rolls each of considerable diameter which is, however, less than the interior diameter of'the cylinder in which it is nested, as shown. 5, 5,indicate the journals for said rolls which are supported in journal bearings having capability of slight movement such as will permitthe rolls'to be forced one toward the other, the construction shown comprising the vertical links 8, 8, supporting journal bearings l8, l0, and pivoted at l, 1, to fixed supports. 8, 8, indicate hydraulic cylinders coupled together in pairs by tension members 88, 88, containing pistons 8, 8, arranged to press upon the journal bearings l0, [8, so that when liquid is forced into one or both cylinders the rolls 4, 4, will be pressed against the interior surfaces of the cylinders 2, 2, and'sald cylinders forced together, with great pressure; The assembly of cylinders and rolls above described may, of course, be rotated in unison by applying power to any one of them, but as shown in Fig. 2 power is conveniently applied by means of the ring gears II, II, connecting the cylinders and a pinion I: on driving shaft l3 of electric motor 7 l4, which pinion meshes with one of said ring gears. Pinion I2 is rotated in such direction that the adjacent surfaces of cylinders 2, 2, and the portions of surfacesof rolls 4, 4, in contact withthe inner surfaces of said cylinders, will allmove upward.

As shown in Fig. 2, the before described con-' struction is inclined to the plane of thehorizon at a considerable angle so that the axes of cylinders and rolls parallel to one another are in the same plane having such inclination. With this arrangement the material to be dehydrated is fed 9,188,880 lustrated in the accompanying three sheets of ward and downward and out of the lower end of saidcylinder I. The dehydrated material willpass upward and to the left over roll 4 and the 1 greaterportion of it be collected in the combined scraper and discharge trough ll -which is in contact both with the surface of the roll and the inner surface of the cylinder. This trough, also would be inclined in a plane substantially material can be discharged from its lower end into sump I8, and the elevator 11 will carry it up into the lower portion of the upper end of the interior of the other, right hand cylinder and therein be subjected to a second stage compression, being ultimately discharged down right hand discharge trough 28. Any material or entrained liquid getting by either of these troughs will, of course, fall into the lower portion of one of the cylinder interiors from the lower end of which it will be discharged by gravity, or if it adheres to roll or cylinder surfaces will be carried around again for another compression stage.

Referring to Figs. 4, 5 and 6 another arrangement is indicated somewhat diagrammatically in which only one hollow cylinder 22, is employed supported on idler bearing wheels 23,; 23, and containing two rolls 24, 24, oppositely disposed so that theirouter surfaces are in contact withthe cylinder interior along lines spaced apart 180 with reference to said cylinder. These rolls may have their journals 25, 25, rotating in journal bearings 80, 38, supported in main frame 2|, with which they have slightly movable connection by reason of horizontally extending slots 3|, 3 l 28, 28, indicate hydraulic cylinders operatively connected each to one of each pair of roll journals, while its piston or ram is operatively connected to the other roll journal of said pair. 5|, 5|, indicate the fluid connections for cylinders 28 through which water or oil can be supplied under pressure to create the desired pressure of roll on cylinder.

Preferably the axes of cylinder and roll are also here inclined to the plane of the horizon and 1 the material to be dehydrated would be delivered v at the lower portion of the upper end of the inout of the lower end of the cylinder. Preferably as shown the lower end of the cylinder may be closed by a plate 34, supported on any convenient stationary pedestal as 45 (Fig. 5) and said plate is provided with a netting covered opening 81 through which liquid may flow into the chute 38. It also has an opening 44 through which the greater portion of the dehydrated material can be discharged into chute 38.

To separate the solid material from the liquid,

I may employ a double-edged scraper 82 of bell crank cross section, pivoted on a stationary shaft 83, which is slightly inclined upward (looking at Fig. 4) from the lower end therein shown so that the lower edge of the scraper, which is slightly curved but substantially parallel to said shaft, will 'run upward and to the left along the inner curved surface of cylinder 22, the scraper edge being curved to ensure contact with said cylinder parallel to. the axes of roll and cylinder and the scraper prevents this material passing over to. mix with the raw material coming in from chute surface at all points in spite of this skewing. The upper edge of said scraper bears upon the downwardly moving surface of the right hand roll 24, and as aresult the solid materials coming from the pressure zone at the left of left hand roll 24 will mainly be arrested by this scraper and, because of its skewed position, asabove described, with its upper end advanced. toward the approaching surface of the-cylinder further than its lower end, this material will be shunted down into the chute 38. The vertical wing, of the 35 on its other side.

To further ensure sufllciently rapid discharge of the dehydrated material a power driven conveyor belt 39 .may be extended through the cylinder interior, being supported from exterior belt pulleys 40 and carrying buckets 4|, 4| of generally triangular shape, as shown in Fig. 4. Preferably the left hand side of this triangular outline would be slightly curved so as to conform to the curve formed by the intersection of the plane of the bucket with the inner curved surface 1 of the cylinder 22.

i To ensure a second stage compression for the bulk of the material another double-edged scraper 26 may be pivotally mounted on shaft 21 with its edges bearing against the opposite surfaces of rolls 24, 24. The mode of operation of this modification therefore would be in general as follows: The raw material coming in through chute 35 on the right hand side of scraper 32 (looking at Fig. 4) would gradually slide lengthwise along the lower interior surface of cylinder 22 and be carried upward to the right by the latters rotation, to be caught between the cylinder surface and the right hand roll 24 and the greater portion of the liquid expressed therefrom, said liquid flowing back and out through netting 31 into chute 36. The solid material would pass up over roll 24 down onto scraper 26 and the greater portion of it carried up over the left hand roll 24 into a second pressure zone where more liquid would be expressed therefrom. The thoroughly dehydrated material would then pass onward down upon scraper .32 over whichv it would be shunted by gravity and the belt conveyor to the discharge chute 38. Any solid matter getting by the lower scraper 32 would go through the entire process again.

Referring to Figs. 7, 8 and 9 another form of power driven ejector apparatus for the dehydrated material is there shown in the form of a differently arranged belt conveyor 59 running one strand located in the interior of cylinder 52 and traveling downwardly along the inclined bottom portion thereof. The buckets 6| on the exterior of said belt would preferably have curved lower edges as shown conforming to the curvature of cylinder 52. The raw material here would be fed in through the chute 56 to the upper end of the cylinder interior, as before, but to the left of the belt strand passing through the cylinder (Figs. 7 and 9). The other three strands of the belt are all outside of the cylinder as shown in Fig. 9.

These figures show the simplest form of my apparatus consisting of only one roll 54 and the cylinder 52 rotating in a clockwise direction on idler wheels 53, 53, as indicated by arrows in Fig. 7. Figs. '7, 8 and 9 show substantially the therefore, be substantially as follows:

from hangers instead of on pedestals. The ref- ,erence characters designating the parts of the pressure-applying mechanism in Figs. 7, 8 and 9 correspond,'for like parts, to those of Figs. 1, 2 and 3, except for the addition of the subscript a. I The strand of the belt 58 inside of the cylinder could be made broad enough to serve as a flexible scraper with its lower edge resting on the inner surface of the cylinder and its upper edge pressed water shedding element 58 on which the expressed liquid would be discharged from the lower end of cylinder, 52. to avoid its mixing with the dehydrated material 41.

The operation of .this modification would,

If the hydraulic or other pressure mechanisms are arranged to act upon cylinders 52 and 54 to force their surfaces together with great pressure, and if the roll and cylinder are rotated in clockwise directions, as indicated by the arrows in Fig. 7, the raw material 48 entering through chute 56, would be picked up by the moving inner surface of the cylinder and carried up into the roll-pass,

the expressed liquid flowing backward and downward and out upon the watershed 58, while the dehydrated material would pass up over "roll 54 and downward to the right hand side of belt 59 which would serve as a partition preventing it mixing with the outfiowing water, or the incoming raw material, while the movement of said belt and buckets 5| would aid gravity in discharging the dehydrate'd material 41 into the chute 51.

If the conveyor belt is dispensed with and gravity feed of the material through thecylinder is relied upon, the incoming material, beingdeposited in a continuous but relatively small stream at the upper end of cylinder 52, would be carried immediately upward and around roll 54, and when dropping down from the upper surface of said roll or cylinder interior, would strike the bottom of the cylinder interior at a point further down and in advance of the material then coming in through spout 56. This operation would be repeated several'times according to the speed of rotation of the cylinder and its diameter before the material ultimatelyreached the lower end of the cylinder and was discharged into chute 51. Thusthe material would follow a helical path from one end of the cylinder towthe other.

Referring to Fig. 10,, two modifications are therein illustrated as follows: Instead of plain cylindrical surfaces for roll and cylinder these,

. Fig, 10. This sectional construction is-alsoindicated at 22a, 22a, in Fig. 4. These sections would be held together by bolts 42, 42, passing through holes 43, of slightly larger diameter in the rings so as to permit the rings to move slightly one over' another. Theadvantage of this construction is that if a particle or small mass of stone, metal or other highly incompressible material gets into 4 f the garbage, the ring of the cylinder construction againstwhich it-"isforded by a roll can spring a trifie toward an elliptical outline to permit it to pass without stopping the operation or breaksome other portion of the apparatus. This local displacement, however, will .only allow a small portion of -material to get by the roll without being sufiiciently compressed, all the other rings retaining their circular outline and functioning normally.

Preferably the pressuremechanisms acting on opposite ends of each roll are independent one. of the other so that each such roll may adjust it; automatically to any position necessaryto give the same degree of pressure to the more compacted material at or near the discharge end of the surrounding cylinder as is given to the more bulky, raw material, being fed into the upper end 'rial may then be passed through a magnetic separator to remove smaller metal objects and these can be'sold as scrap iron, while the final residue is put through a mascerator which will cut up the vegetable, animal and other soft mate- 'rials into pieces not over about two inches in maximum dimensions." This partly mascerated mass is then fed to the dehydrator above described. The end -product from said dehydrator may be further dried out by heat, if necessary, when it is to be used for fuel, and thereafter put -through a pulverizer before being delivered to the pulverized fuel burning furnace, Such heat treatment can be done without the liberation of odorous fumes or heavy smoke such as render the ordinary burning of garbage in the usual form of incinerator a public nuisance. This resuits from the fact that practically all of the fermenting constituents of the original mass have been previously squeezed out in liquid solution.

Moreover even this short heat treatment may be dispensed with if the final .residue is to be used in making cellulose products, as it will then be treated with an acid solution, or some other chemical reagent in solution, and the presence of a small percentage of residual moisture in the material is then no disadvantage, being easily compensated for (perhaps) by the use of less water in the reagent solution.

- A basic advantage of my present invention results from the fact that in all stages of operation (except that occurring while the material is passing down around the left hand roll shown in Fig. 4) the expressed liquid automatically flows down and away from the solid material being acted ori in the pressure zone. This function of the apparatus and its resulting advantages are broadly new so 'far as I know and are sharply distinguished from the operation of an ordinary rollr press through which the material must be fed downwardly, with the result that the expressed liquid is temporarily trapped in the upper portions or just above the pressure zone, whereit backs up into the downwardly moving raw material and thereby saturates the latter to a degree greater than that existing brought to the press.' Consequently. h further rawmaterial goes into the old roll press the more liquid per unit of volume thereof is present therein to be expressed at the final, narrow line of pressure where the convex sin-faces of the rolls meet. With my apparatus on the other hand, such action is reversed, and also the period wad Kit was i of greatest, and aproximately greatest, pressure is materially prolonged.

Various changes could be made in the details 01' construction of the apparatus above described as constituting mypreferred embodiment of the invention and some of the. described details omitted without departing from. the substance and underlying principles thereof, so long as the basic idea of means disclosed is employed and the various possible further modifications are within the definitions of any of the appended claims.

As shown in the drawings (Fig. 2) the preferred angle of inclination to the plane of the horizon of the axes of both cylinder 2 and roll 4, is but this might be varied within limits, and even reduced practically to zero. I have found 15 to be the preferable angle because that produces sufiiciently rapid and effective drainage for the expressed liquid, while avoiding any excessive sliding downward of the raw material lengthwise of the cylinder before it enters the zone of compression. Obviously, if the angle were increased to a point at which the downward pull of gravity on such material toward the lower, discharge end of any of the cylinders 2 exceeded the coefilcient of friction thereof on the interior surface of the cylinder, much of the material would slide downward toward, and possibly all the way to and out of, the discharge end of the cylinder as soon as deposited therein, and no material would be carried up to the higher end of roll 4, thus preventing the apparatus working at full efficiency and allowing an indeterminate part to go through without any pressing action thereon, if no bottom face plate 34 were used.

Also, if the angle exceeded 45, and the end plate 34 were used, most of the material might slide down against said plate as soon as it was deposited in cylinder 2, or at least before it was lifted to the compression zone by the inner surface of such rotating cylinder. This would bunch the material at the lower end of the cylinderand choke the apparatus, or atleast leave its upper half (nearest the entrance point of the material) running empty.

Among other important novel features of my improved apparatus may be mentioned the location of the in-feed for the raw material at the lower portion of the end of the hollow cylinderat the higher end of said cylinder if it is inclined, and placing the axes of cylinder 2 and roll 4 nested therein at substantially the same elevation so that this line of contact is similarly elevated. This leaves an open space beneath the roll into which the raw materials may be introduced in regulated quantities upon the moving lower, inner surface of the cylinder, and on and by it carried up to the much higher compression -zone. As any particular area ofsuch bearing surface becomes more and more sharply inclined to the plane of the horizon as it approaches the compression zone, the upper layers of any excess of material so carried thereon will tend to sag backward by gravity and so automatically tend to prevent the delivery of any undesirably thick layer thereof to the narrow zone of maximum pressure.

. advantage results from the factthat enormous pressures (as much a 9000 lbs.) per linear inch of roll surfaces in contact can be applied without the material slipping back, away from the line of maximum pressure which. it is approaching. Consequently suiiicient pressure per square inch can be applied to break downthe cellulose or other cells and transform them into fine, amorphous particles from which any liquid trappedin the original cells and not expelled by mere pressure can be easily andrapidly evaporated by air drying, Thus, a sheetiof old newspaper run flat into my apparatus comes out as a disintegrated layer of amorphous'cellulose which has no more coherence than so much soft soot.

' In an arrangement as shown in Figures 1 to 3 but with the exterior surfaces of the rings actually in contact, either one of the rings or hollow cylinders 2 serves as a roller bearing for the exterior of the other which is forced against it by the hydraulic pressure exerted through one of the rolls 4 and the latters journals and journal bearings. Taking either roll 4 and its surrounding cylinder together with the other cylinder and the hydraulic pressure system, they constitute a pressure roller mill in which the second cylinder is really a roller backing for the first cylinder to which latter the operating roll pressure is applied.

by roll 4 within it. Substantially the same floating roller bearing system is formed by the single cylinder 22 and two rolls 24 therein shown in Fig. 4. In this way the structural difiiculty in creating the necessaryvery great pressure between an internal roll and an openended cylinder or ring surrounding it (and therefore necessarily devoid of axial journals and journal bearings) is practically overcome.

Having described my invention, 1' claim:

1. A mechanical dehydrating apparatus, comprising an imperforate revolvable hollow cylinder having an annularly smooth inner surface, an imperforate revolvable roller; of somewhat less external diameter than the internal diameter of said cylinder and having an annularlysmooth outer surface, positioned therein and always in contact with the inner surface of said cylinder except when material is being pressed therebetween, the line of contact of the roller and cylin-, der being substantially in a plane containing the axes of the roller and cylinder, said plane being substantially normal to the plane passing through the axis of the cylinder and the lowest pointin its inner surface, means for forcing said surfaces toward each other with great but yielding pressure, means for positively rotating one of said revolvable members in such a direction that material to be dehydrated may be fed into the lower portion of the hollow cylinder.

2. A mechanical dehydrating apparatus, comprising an imperforate revolvable hollow cylinder having an annularly smooth inner surface, an imperforate revolvable roller, of somewhat less external diameter than the internal diameter of said cylinder but at least equal to the radius of the cylinder and having an annularly smooth outer surface, positioned therein and always in contact'with the inner surface of said cylinder except when material is being pressed therebetween,- the line of contact of the roller and cylinder being substantially in a plane containing the axes of the roller and cylinder, said plane being substantially normal to the plane passing through the axis of the cylinder and the lowest point in its inner surface, means for forcing said surfaces toward each other with great but yielding pressure, means for positively rotating one of said revolvable members in such a direction that material to be dehydrated may be fed into the lower portion of the hollow cylinder.

3. A mechanical dehydrating device as defined in claim 1 in which the plane of the axes is inclined to the horizontal in a direction longitudinally of the axes. a

4'. A mechanical dehydrating device as defined in claim 1 in which the plane of the axes is inclined to the horizontal at anangle of about '15 in a direction longitudinally of the axes.

5. A combination'such as defined in claim 1 in which said axes are inclined at an angle of about to the plane of the horizon.

6. An apparatus such as defined in claim 1 in which said axes are inclined to the plane of the horizon, combined with power driven means for ejecting dehydrated material from the lower portion of said cylinder.

7. An apparatus such as defined in claim '1 combined with a'conveyor belt located in the lower portion of the interior of said cylinder, and means for causing said belt to travel lengthwise of said cylinder so as to eject dehydrated material therefrom.

8. An apparatus such as defined in claim 1 combined with a conveyor beltlocated in the lower portion of the interior of said cylinder, and means for causing said belt to travel lengthwise of said cylinder so as to eject dehydrated material therefrom, said belt running over pulleys having axes perpendicular to the axis of the cylinder, and being provided with conveyor scrapers projecting from one face thereof, one strand of said belt being arranged to travel along a portion. of the lower inner surface of said cylinder which extends substantially parallel to the axis thereof, and the said feeding means being arranged to deliver the material to be dehydrated to the interior of the cylinder on that side of said belt strand away from which the surface of the cylinder is traveling; whereby said belt strand forms a partition for keeping the dehydrated materials separate from the incoming damp masses of material to be dehydrated.

9. A combination such as defined in claim 1 in which said cylinder is composed of a plurality of rings of elastic metal capable of slight radial movement one on another; whereby any one of said rings may be slightly deformed from circular to substantially elliptical outline by the passage of a partly incompressible body of matter between it and the roll without similar deformation of the remaining rings.

10. A mechanical dehydrating apparatus, comprising an imperforate rotatable hollow cylinder having a smooth annular surface, two rotatable rollers, eachof somewhat less external diameter.

tially the same vertical elevation as the axis of the cylinder, means for forcing said surfaces into contact with great but yielding pressure, means for rotating the cylinder and rollers, and means for feeding the material to be dehydrated to the,

hollow cylinder at an elevation below the rollers. 11. An apparatus such as defined in claim 10 prevented from being carried onward to mix in with the incoming untreated material.

12.' An apparatus such as defined in claim '10 combined with a double edged scraper located in saidcyl'inder and bearing on the surfaces of both rolls at such inclination thereto that material.

thereby scraped oi! the surlace of one roll shall be nroiected'against that or the other and thereby and thereafter carried into'contact with the cylinder'wall tor subjection to a second ompres sion therebetween.

13. A combination such as deiined in claim 10 including means for forcing one roll'away from the other which comprises an hydraulic apparatus one element of which is operatively connected to the journal bearings or one or said rolls, while another relatively movable element is operatively connected to the journal bearings of the other roll, said Journal bearings being capable of slight movement toward and from one another.

EARLE I". ALLEN. 

